Biochemical Basis Of Islet Beta-cell Compensation And Failure In Normal Pregnancy And Gestational Diabetes Mellitus
Funder
National Health and Medical Research Council
Funding Amount
$480,828.00
Summary
The factors causing the current world-wide crisis of rapidly rising diabetes prevalence remain poorly understood. Of potential major importance, however, is the hypothesis that abnormalities in the maternal metabolic environment, as occur in gestational diabetes (GDM) (diabetes that develops in pregnancy), result in abnormal development of metabolic systems in the baby resulting in higher risk of adult onset diabetes in the babies. Therefore, it is of importance to understand the mechanisms caus ....The factors causing the current world-wide crisis of rapidly rising diabetes prevalence remain poorly understood. Of potential major importance, however, is the hypothesis that abnormalities in the maternal metabolic environment, as occur in gestational diabetes (GDM) (diabetes that develops in pregnancy), result in abnormal development of metabolic systems in the baby resulting in higher risk of adult onset diabetes in the babies. Therefore, it is of importance to understand the mechanisms causing GDM, such that effective measures can be developed to counter this passing on of diabetes risk from mother to baby. It is known that a key factor causing GDM is failure of maternal pancreatic islet beta-cells to compensate for increased demands for insulin production in pregnancy. Poorly understood, however, are the cellular mechanisms of islet beta-cell compensation in normal pregnancy and failure of this compensation in GDM pregnancy. We have recently shown that there is a pathway of fat metabolism (triglyceride- free fatty acid cycle) within the islet beta-cell that has an important role in amplyfing insulin secretion necessary to maintain normal blood glucose and protecting the islets from failure in obese rats. The major focus of this project is to test the hypothesis that this pathway has a key role in the adaptation of pancreatic islets to normal pregnancy and its dysfunction contributes to the causation of GDM. Of great interest from preliminary findings is that a master regulator of glucose and fat metabolism, PGC1alpha, is markedly reduced in islets during normal pregnancy. Studies will also be directed to PGC1alpha's role in islet adaptation to pregnancy and failure in GDM. We expect that successful completion of this project will lead to the development of highly targeted counter measures to prevent GDM and to slow and reverse the current epidemic of diabetes.Read moreRead less
The Role Of Linked Cytokines In T Helper Cell Differentiation
Funder
National Health and Medical Research Council
Funding Amount
$390,504.00
Summary
An important class of T cells known as T Follicular Helper cells (TFH) orchestrate the immune response so that we can produce antibodies to fight infection. The novel finding that our Lab made last year is that the molecule interleukin 21 (IL-21) is a growth factor for TFH. The findings we have made thus far could be used in a number of ways. For eg, IL-21could be used to expand numbers of TFH, using them to boost vaccination or natural defences against viruses, bacteria and tumour cells.
Expansion, Differentiation And Functional Analysis Of In Vitro Derived Pdx1+ Pancreatic Progenitors
Funder
National Health and Medical Research Council
Funding Amount
$540,075.00
Summary
Type 1 diabetes is a condition that arises when the body's immune system destroys insulin-producing beta cells within the pancreas. Recent studies have shown that normal glucose control can be restored by replacing the missing beta cells by transplantation of cells from deceased donors. However, the demand for transplant material outweighs supply. The work described in this application seeks to define how insulin-producing beta cells can be derived in the laboratory from embryonic stem cells .
Apoptotic Pathways In Pancreatic Beta Cells Leading To Type 1 Diabetes And Transplant Rejection
Funder
National Health and Medical Research Council
Funding Amount
$535,333.00
Summary
The destruction of insulin-producing beta cells in the pancreas by immune cells leads to the need for daily insulin injections in patients with type 1 diabetes. This project aims to understand how beta cells are destroyed. A knowledge of the process by which this occurs will indicate ways we can protect these cells. Our previous work has suggested strategies that may protect beta cells, and we aim to test these. Such protection may eventually allow beta cell replacement by transplantation.
The Role Of T-cell Apoptosis In Transplantation Tolerance
Funder
National Health and Medical Research Council
Funding Amount
$173,380.00
Summary
Organ transplantation is the treatment of choice for patients with end-stage heart, lung, liver or kidney failure and there have been spectacular improvements in the early success of these procedures. However the 10 year graft survival rate has not changed much in the past 15 years. One way of overcoming this problem is to manipulate the immune system so that the transplant is accepted indefinitely. This is called tolerance and it works by giving intense immunosuppression for a short period so t ....Organ transplantation is the treatment of choice for patients with end-stage heart, lung, liver or kidney failure and there have been spectacular improvements in the early success of these procedures. However the 10 year graft survival rate has not changed much in the past 15 years. One way of overcoming this problem is to manipulate the immune system so that the transplant is accepted indefinitely. This is called tolerance and it works by giving intense immunosuppression for a short period so that the transplant is accepted indefinitely without the need for long term immunosuppression. The immune mechanism responsible for this phenomenon is complex and is poorly understood. This project aims to study the early events in the immune system that leads to transplantation tolerance. In particular, factors involved in programmed cell death in white blood cells will be studied. Specially bred mice that have blocks in the cell death mechanisms will used to determine what effects these blocks have on the ability to induce tolerance. Other mice that have been genetically altered to allow their white cells to be tracked will be used to study the fate of these cells. If the mechanisms involved in tolerance induction are better understood, then it will be possible to design specific immunosuppressive drugs that will be used to produce tolerance in transplant patients.Read moreRead less
Understanding The Development Of Pancreatic Islet Cell Tumours
Funder
National Health and Medical Research Council
Funding Amount
$579,163.00
Summary
We will use mouse models of pancreatic cancer that we have established previously to investigate the molecular basis of the development and progression of tumours in the insulin-producing cells of the pancreas. We propose to manipulate a small number of candidate genes using established islet cultures and new mouse models in order to characterise the effect they have on islet cell biology and tumorigenesis.
To Determine The Means By Which Plasminogen Activators Modulate Integrity Of The Blood Brain Barrier
Funder
National Health and Medical Research Council
Funding Amount
$523,084.00
Summary
Tissue-type plasminogen activator (t-PA) is used clinically to remove blood clots. However, t-PA can also cause brain injury and influence the blood brain barrier (BBB) which has implications for the treatment of patients with ischaemic stroke. This project will use in vitro and in vivo models to understand the mechanism by which t-PA modulates the BBB. A novel tPA variant will also be created that ultimately may be of benefit for patients with ischaemic stroke.
The Role Of The Intestinal Epithelium In Gliadin Peptide Influx In Coeliac Disease
Funder
National Health and Medical Research Council
Funding Amount
$503,566.00
Summary
Food products made from cereals such as wheat are part of the staple diet for much of the world but unfortunately they trigger coeliac disease in 1:100 individuals including more than 100,000 Australians. This project aims to determine where the disease inducing proteins cross the cells that line the intestine to enter the body. It also aims at increasing the health of these cells to produce a barrier that can prevent the disease inducing proteins from entering the body.
Mechanisms Of Fatty-acid Mediated Destruction Of Pancreatic Beta Cells
Funder
National Health and Medical Research Council
Funding Amount
$510,476.00
Summary
Type 2 diabetes is associated with obesity, but not all obese individuals develop the disease. Non-diabetic obese subjects are able to compensate for diminished sensitivity to insulin (a general feature of obesity) by enhanced output of insulin from the pancreatic beta-cells of the islet of Langerhans. In diabetics this compensatory mechanism is disrupted. Obesity and Type 2 diabetes are also associated with elevated levels of fatty acids (FAs) in the bloodstream. These can be taken up by the be ....Type 2 diabetes is associated with obesity, but not all obese individuals develop the disease. Non-diabetic obese subjects are able to compensate for diminished sensitivity to insulin (a general feature of obesity) by enhanced output of insulin from the pancreatic beta-cells of the islet of Langerhans. In diabetics this compensatory mechanism is disrupted. Obesity and Type 2 diabetes are also associated with elevated levels of fatty acids (FAs) in the bloodstream. These can be taken up by the beta-cells where they exert both short and long-term effects. In the longer term FAs can be toxic to beta-cells and this is thought to be important in the failure of beta-cell compensation. The project is aimed at a better understanding of the manner by which different types of FAs influence the susceptibility of beta-cells to destruction. It builds on our preliminary results suggesting that the capacity of the beta-cell to convert saturated FAs to unsaturated FAs helps protect them from destruction. Our aim is to examine the mechanisms underlying this protection.Read moreRead less